The present invention relates to an electro-optical device, and particularly, to a display technique to provide an image display having a high definition and good color reproduction even on a large-size screen.
Recent flat panel displays provide high-definition and high-quality images even on a large-size screen. Particularly, in the field of plasma displays or liquid crystal displays, fabrication technology for thin film transistor (TFT) devices have been improving in feature size and production yield even with large-size wafer, so that large-size screen displays are installed in various places.
Conventionally, image processing devices that convert grayscale image data into binary image data by using quantization methods such as “error diffusion” and “minimized average error” have been proposed for realizing high-definition and good-color-reproduction images. In the first example of relate art, an image processing device that has a means of fixing problems such as delay effect in generating dot and tailing artifact on the edge of low and high density regions by setting threshold values of quantization in the low and high density regions.
Japanese Unexamined Patent Publication No. 8-307680 (paragraph 0018, etc.) is the first example of related art. Japanese Unexamined Patent Publication No. 9-163141 (paragraph 0047 to 0050, etc.) is the second example of related art.
However conventional display devices can provide high definition and good color reproduction only with proper range of distance and angle of view. Recent demands for installing ultra-large-size displays in various places hint some disadvantages of the conventional.
Firstly, today's typical display devices are designed to provide high-definition and good color-reproduction images assuming that the whole screen is captured inside the sight of viewers with some margins of view angle and distance. However, recently, there can be scenes where viewers closely observe such high-definition and good color-reproduction images. For example, high-definition and good color-reproduction images can be displayed on the wall of a corridor that might force passengers to closely take a look. In such situations, it is quit difficult for the conventional devices to simultaneously provide both ultra wide view and high-definition good-color-reproduction images.
In addition, since definition (resolution) is specific to display device, images that is originally created for target display devices can hardly fit other display devices, which has different definition.
Further, since the larger size display device even with high definition the related arts got to realize, the more the device should weigh and cost, it has been impossible to realize a display that is as huge as a sidewall.
Furthermore, the related arts could not fix the problems inherent in a huge complex-screen display device that is claimed in this application and comprises a plurality of tiles, each of which is a display device manufactured by using low-temperature poly-silicon TFT technology or the like. One of the problems is that the difference in color reproduction between tiles caused by deviation in transistor characteristics can be captured by human vision on the edge of connecting line of tiles.
The first and second references of related arts that are related to enhancing color reproduction by quantization of source image data are mainly dedicated to printing devices and present no specific configurations for display devices.